1. Field of the Invention
The present invention relates to a method of inspecting that is executed when manufacturing a high-density integrated circuit such as an LSI, super-LSI, etc. or a photo-mask, etc.
2. Description of the Related Art
As the quality inspection that is performed when manufacturing a photo-mask, there are dimension inspection, coordinate inspection, defect inspection, etc. Since those kinds of inspections is performed by using a method of radiating a laser light onto the photo-mask and thereby performing relevant measurement or is performed by performing relevant measurement with use of an electronic microscope, they have hitherto been performed with respect to a respective one of the individual photo-masks that have been manufactured.
However, since the inspection method using a contact-type measuring instrument, or the inspection method performing inspection by cutting a photo-mask and inspecting the resulting cross section, etc. are likely to damage the surface or cannot be performed unless the photo-mask is destroyed, each of those inspection methods had a problem in that it is impossible to perform quality inspection.
Also, in each of those inspection methods, there is the possibility that, after inspection of the photo-mask, foreign matter will attach onto it. In addition, even the photo-mask whose measured result has been good after measurement must be re-cleaned, and a plurality of inspections cannot be simultaneously performed, and so forth. Each of those inspection methods, therefore, had a problem from the viewpoint, as well, of the operation efficiency.